1. Field of the Invention
This invention relates generally to an adjustable steering column assembly for use in a motor vehicle. More particularly, the present invention relates to a mounting assembly for adjusting the reach and height of the steering column assembly.
2. Description of the Related Art
It is important that steering columns in motor vehicles be rigidly mounted in the vehicle to avoid the occurrence of vibration or resonance in the column. This can be done by making the column components relatively massive, but this is undesirable for a number of reasons. It is also necessary that the column be adapted for simple assembly into the vehicle on an assembly line.
A variety of adjustable steering column assemblies have been proposed to overcome the problems of vibration and resonance in the steering column. One such assembly is known from European Patent Application EP-A-0 050 999 in which a beam structure extends between the two column mounting points. In this assembly however, the position of the beam is fixed and the column moves relative to the beam when the column position is adjusted.
Great Britain patent No. 2,113,629 discloses a mounting assembly for an adjustable steering column wherein a support member on the steering column and a bracket member attached to the vehicle chassis includes a pair of slots extending generally at right angles to each other. The members are connected together by a pin passing through the slots of both members. In this manner, the steering column can be adjusted perpendicularly and parallel to the longitudinal axis of the steering column by loosening a clamping device found on the steering column. The clamping device comprises a sliding block mounted on a pin and a slot of either of the members. Clamping faces are formed on the sliding block and the other member.
Great Britain Patent No. 2,113,164 discloses another adjustable steering column mounting assembly having a support for rotatably carrying a steering column member and a bracket carrying the support. The support moves relative to the bracket in two mutually perpendicular directions. The mounting assembly further includes a clamping device for clamping the bracket to the support, characterized in that two rack and pinion sets are connected between the bracket and the support such that movement of the support relative to the bracket in each of the mutually perpendicular directions causes the pinions to roll relative to the racks of the respective rack and pinion sets. The clamping device increases the frictional forces opposing the relative movement of the rack and pinion.
It is an object of the present invention to provide an adjustable steering column mounting assembly in which a substantial proportion of the load typically carried by the steering shaft and surrounding casing are transferred to a beam secured to the vehicle chassis so that the steering shaft can be designed to optimize other requirements placed upon it.
It is an advantage of the present invention that only a single fastener need be released to enable both both the height and reach of the steering column to be adjusted. These and other features and advantages of the present invention will be disclosed in the following summary, drawings and detailed description of a preferred embodiment which follow.